Yes, Gionee X1 does have the Extreme Power Saving Mode, which helps your phone battery to last longer in case of emergency.
Yes, Gionee X1 does have the screen record functionality.
Yes, Gionee X1 does have a LED flash for the selfie camera.
No. Gionee X1 has 2 dedicated slots for the Sim cards and one dedicated slot for the memory card. You can expand phone memory by up to 256GB with the help of the MicroSD card.